(a) Field
The following description relates to a pixel, a display device including the pixel, and driving method of the display device. More particularly, the following description relates to a pixel including an OLED (organic light emitting diode), an active matrix display device including the pixel, and a driving method of the display device.
(b) Description of the Related Art
One frame of the active matrix display device includes a scan period for programming image data and a light emission period for emitting light according to the programmed image data.
However, as the size and resolution of the display panel increases, the more the RC (resistive-capacitive) delay of the display panel increases. Accordingly, it takes more time to program image data in each pixel of the display panel, and it becomes more difficult to drive the display device.
Further, driving the display becomes more difficult when the display device displays a stereoscopic image.
When displaying a stereoscopic image, for example, under the NTSC standard, the display device should alternately display sixty images for the left eye and sixty images for the right eye per second. Therefore, the driving frequency of the display device displaying a stereoscopic image is at least two or more times that of the display device displaying a plane image.
Because data programming should be finished within at least 1/120 of a second when a stereoscopic image is displayed, a drive that scans the entire display panel during a single scan period and operates at a high driving frequency to program image data is required. A driver with a high driving frequency causes the manufacturing cost to be increased.
Further, the larger the area of the display panel, the larger the area that the organic light emitting diode (OLED) occupies, and therefore, the parasitic capacitance increases such that the compensation time for the threshold voltage increases, which reduces light emitting duty. Thus, the power consumption of the display panel may be increased.
Further, a backward voltage is applied to an organic light emitting element while driving during a reset period, potentially causing black spots to appear on the display, and black spots may also appear during a compensation period for the threshold voltage. Further, a swing in the power source voltage during the driving may influence the operations of various other control signals due to coupling, and a deterioration of the image quality of the display, such as loading of a dark part, due to the coupling may occur.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.